说明：  本软件设计D触发器的目的和任务：1.使学生全面了解如何应用该硬件描述语言进行高速集成电路设计；2.通过软件使用、设计与仿真环节使学生熟悉EDA-VHDL开发环境；3. 通过对基本题、综合题的设计实践，使学生掌握硬件系统设计方法（自底向上或自顶向下），熟悉VHDL语言三种设计风格，并且培养学生应用VHDL语言解决实际问题的能力。
(The software design of D flip-flop of the purpose and tasks: 1. To enable students to fully understand how to apply the hardware description language for high-speed integrated circuit design 2. Through the software, design and simulation aspects so that students are familiar with EDA-VHDL development environment 3. through the basic questions, integrated design practice questions so that students master the hardware system design approach (bottom-up or top-down), are familiar with VHDL, three kinds of design style, and the application of VHDL language students to solve practical problems.)